Folding apparatus for a cardboard blank



United States Patent inventor Pierre Lang I Ecublens, Switzerland Appl. No, 728,557 Filed May 13,1968 Patented Sept. 22, 1970 Assignee J. Bobst et Fils S.A.,

Prilly, near Lausanne, Switaerland Priority Mriy24f1967 Switzerland FOLDING APPARATUS FOR A CARDBOARD BLANK I Fl I 19 1 1404 --.1.

[56] References Cited UNITED STATES PATENTS 2,911,889 11/1959 Welsh 93/52X 3,079,144 2/1963 Frei 93/84 3,110,232 11/1963 Frei 93/84 3,269,092 8/1966 MacDonald 93/ 52X 3,377,926 4/1968 Propper 93/49 3,377,927 4/1968 Propper 93/84X 3,389,645 6/1968 Winters et a1... 93/52X 3,416,285 12/1968 Standley et al. 93/49 3,417,666 12/ 1 968 Waterhouse 93/52 3,430,413 3/1969 Wood... 93/1. 1X

Primary Examiner-Wayne A. Morse, Jr. Attorney-Hill, Sherman, Meroni, Gross and Simpson ABSTRACT: A device for folding a rearwardly extending flap at an edge of a blank onto the blank as the blank is being advanced, wherein there is provided a member which engages another portion of the blank as the flap is being folded to hold the edge of the blank in position while the flap is being folded.

Patented Sept. 22, 1970 3,529,515

Sheet 1 01'2 I Fig 1,PRlORART Fig.2.PRlORART Patented Sept. 22, 1 970 Sheet Fig.4

FOLDING APPARATUS FOR A CARDBOARD BLANK BACKGROUND OF THE INVENTION l Field of the Invention The invention generally relates to apparatus and methods for folding a portion of a foldable piece of material.

More particularly. the invention relates to methods and apparatus for folding a rearwardly extending flap at and along a lateral edge of an advancing blank through approximately l 80 forwardly onto the blank.

2. Prior Art In the known arrangements the area of the blank adjacent the intersection between the blank and the flap is unrestrained and consequently when there is an attempt to foldthe flap in this area not only does the entire edge or fold line become bent or deformed but the adjacent portionof the blank is also raised.

SUMMARY OF THE INVENTION An object of the invention is to provide methods and apparatus which will overcome the above deficiency by restraining the lifting or raising of the portion of the blank adjacent the edge which will be formed by the folded flapand blank while permitting the folding of the flap.

In accordance with the invention the blank is advanced in a longitudinal forward direction with a flap extending rearwards at an edge of the blank and while so moving the flap is acted on by a folding means such as a pivotal lever or air jet which causes theflap to fold forwardly about 180 about a fold line to a position above the portion of the blank to which the flap is attached. Thus folding is carried out accurately and efficiently because a blank restraining means is provided to act in cooperation with the folding means by contactingthe blank. as the flap is being folded. in the region of the fold line and exerting pressure on the blank to hold the edge in position as the flap is being folded. The restraining means is synchronized sure the desired accurate and efficient fold.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects. features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof. taken in conjunction with the accompanying drawings. although variations and modification may be effected without departing from the spirit and scope of the novel concepts of the disclosure, and in which:

FIG. 1 is a plan view of a known arrangement for advancement of a blank;

FIG. 2 is a perspective view of a portion of the rear of a blank showing the folding of a flap at a lateral edge of the blank according to the prior art and illustrating how the unrestrained blank is raised or lifted when the flap is being folded;

FIG. 3 is a view having a perspective similar to FIG. 2 but showing the arrangement according to the present invention; and

FIG. 4 is an elevational side view of the arrangement of the present invention shown in FIG. 3.

BRIEF DESCRIPTIONOF THE PREFERRED EMBODIMENTS In order to fully understand the invention it is helpful to consider first the folding apparatus as known in the art and as shown in FIGS. 1 and 2.

In FIG. 1 there is shown a blank piece of material 1 having three rearward extending flaps 2. 3. 4 which are to be folded forwardly onto the main portion of the blank. The blank many times is constituted of a foldable material such as cardboard or the like.

The flap 2 is centrally located along the rear folded edge portion of the blank and the flaps 3 and 4 are located along the folded edge adjacent the lateral edges and on opposite sides of the central flap 2. A greater number of flaps may be provided but there will always be at least one flap located at a lateral edge. Many different objects. e. boxes may be formed of the blank I and this determined the number of flaps.

As shown in FIG. I the blank 1 is advanced in the direction of arrow 5 by pairs of conveyor means 6 and 7 respectively which means may include belts or rollers contacting opposite surfaces of the blank. The conveyor means v6. 7 are provided in the region of lateral flaps 3 and 4 to hold them while the flap 2 is being folded onto the remainder of the blank about the fold line 2a until it assumes a position as shown at 2'. The conveyors 6 and 7 hold the blank I taut and flatduring the operation of the folding of flap 2 onto the remainder of the blank.

However. as shown in FIG. 2 when the flaps 3 and4 are to be folded subsequently. the lateral edge portions of the blank 1 are unsupported. Thus. as shownin FIG. 2 the blank with the folded flap2' is now advanced by a central conveyor means8 havingbelts which contact the blank on opposite surfaces and thereby transport the blank longitudinally therewith. The lateral edges are unsupported. When a folding means 9. which may be a lever. air jetor the like. acts on flap 4 to fold the same abouta fold line 4a theentire edge of the blank will be raised and deformed as shown at 1 in FIG. 2.

The present invention seeks to obviate this drawback of the deforming or raising of the blank when the flaps at the lateral edges are fold'edr In accordance with-the invention there is shown in FIG. 3 the blank 2L being advanced by conveyor 28, the flap 22 having been already folded to assume a position as shown at 22'. The blank 21 is supported on the auxiliary lateral conveying belt; 10. A pivotal lever 11 which moves inthe direction of arrow I2 here shown movingcounterclockwise acts on flap 24 to raise the same about a fold line 24a and then fold the flap downwards onto the remainder of the blank.

It is to be understood that if the blank has flaps at both lateral edges-or at other portions of the blank there will be at least a second pivotal lever on the other side of the blank to fold the second flap and other flap folding means in operative proximity to any other flaps.

Mounted adjacent the advancing blank is a support stem 13 which is adjustably supported from a fixed frame in a well known manner. Referring to FIGS. 3 and 4 it will be seen that a block 14 is mounted on stem 13, which block supports a bearing in which is mounted a rotatable memberhaving opposite arms l5, 16. The rotatable member is driven in the direction of arrow 17 by the shaft 18 which may be rigid or flexible. Preferably, the drive shaft 18 is flexible to enable ready adjustment of the position of stem 13 and in turn to enable adjustment of the position of block 14 and arms I5, 16 of the rotatable member.

The position of block 14 is such that the arms 15, 16 describe a circular are which is restricted to the region 2l"-of the blank proximate the lateral edge thereof. The arms l5. l6 rotate in a plane which is immediately above the fold line of flap 24.

As shown in FIG. 4 the plane of rotation of the arms 15, 16 is inclined slightly downwards with respect to the plane of the blank. The arrangement is such that as the flap 24 is being folded by the lever 11, the arm 15 or 16 is in contact with the blank in the region just ahead of the fold line 24a to hold the edge of the blank in its plane and preventing raising thereof. The path of the rotatable member insures that arm 15 or 16 will remain in contact with the blank as the blank is being advanced until the flap 24 has been folded through a sufficient angle so that there is no longer any tendency for the edge of the blank to be raised. The arms 15, 16 are constituted as elastic blade members to cause them to apply pressure on the blank to impede raising of the edge of the blank during folding of flap 24.

The operation of the rotatable member is synchronized with the pivotal lever I1 and the advancing blank 21 so that the contact of the arm 15 or 16 with the blank will be made before the flap 24 has been lifted and will remain in contact with the blank adjacent the flap until the lever 11 no longer tends to raise the edge of the blank. Obviously. the positioning of the rotatable member is of substantial importance and hence the adjustability of stem 13.

Although a rotatable member with opposite arms 15 and 16 has been shown. obviously a single arm is sufficient. or three or more arms can be employed. Of course. the rotation speed of the rotatable member is adjusted to the number of arms and the speed of the blank.

Since there are generally two flaps at the laterial edges of the blank. a second rotatable member 14 as shown in dotted lines similar to that already described will be placed at the other side of the central conveyor 28. ln such case the rotatable members may be connected by a flexible drive element 19 shown in dotted lines whereby the drive at shaft 18 will be sufficient to drive the two rotatable members in appropriate directions. The flexible element l9 makes it possible to adjust the spaced positions of the rotatable members to accommodate blanks of different widths. lengths and configurations.

Although minor modifications might be suggested by those versed in the art. it should be understood that 1 wish to embody within the scope of the patent warranted hereon all such modifications as reasonable and properly come within the scope of my contribution to the art.

lclaim:

1. An apparatus for folding a flap portion about an edge of a moving, generally coplanar blank comprising a conveyor means adapted to advance in a longitudinal direction a generally planar blank of material having at least one initially generally coplanar flap portion extending outwardly along a line of fold which will be at an edge of said blank when said flap is folded and which blank and flap portion each have generally coplanar opposite first and second planar surfaces. folding means for acting on said first surface of said flap portion of the advancing blank to rotate the flap portion about said fold line and out of the plane of the blank. and restraining means synchronized with said folding means and said conveyor means to contact the blank on said second surface thereof in the region of said fold line as said blank is advancing and thereby restrain the blank from moving out of its plane of advancement as the folding means contacts the flap portion to begin the rotation of the flap about said fold line, said restraining means for holding the edge of the blank in position while the flap is being folded comprising an elongated rotatable arm member which rotates in a plane and contacts the blank in the region of said fold line as said blank is moving, said plane of rotation of the rotatable member being inclined with respect to the plane of the blank to exert forces on the blank to resist any tendency of the blank to be raised.

2. An apparatus according to claim 1 wherein the portion of said rotatable arm member contacting said blank rotates from a position not directly above said blank second surface to a position over and contacting said second surface of said blank.

3. An apparatus according to claim 1 wherein the flap is folded approximately 180 out of the plane of the blank to a position above said second surface and in a parallel relation thereto juxtaposed to said blank, said arm member moving and remaining in contact with the blank until the folding means no longer tend to raise the blank.

4. An apparatus according to claim 1 wherein said rotatable arm member comprises a flexible blade.

5. An apparatus according to claim 1 wherein a plurality of rotatable arm members rotate about a common axis of rotation whereby each arm member may alternately operate to contact said blank in a region of a fold line.

6. An apparatus according to claim 5 wherein each of said arm members is a resiliently flexible blade and each rotates in a common plane.

7. An apparatus according to claim 1 wherein the position of said restraining means is adjustable relative to the plane and width of the advancing blank. and wherein a driving force is imgarted to said rotatable member by a flexible drive means.

. An apparatus according to claim 1 wherein said folding means comprises a pivotal member which contacts the flap to fold the same out of the plane of said blank. said folding means being provided in a number to correspond in a manner and position'to the number of flaps extending outwardly along lines of fold on a blank and wherein said restraining means is provided in a number for holding the blank in the region of each of said fold lines.

9. An apparatus according to claim 8 wherein said number of folding means and restraining means comprises one of each disposed on opposite sides of said conveyor means so as to act on flaps adjacent a lateral edge of said blank.

10. An apparatus according to claim 1 wherein said rotatable arm member is generally straight except for a blank contacting portion which is at an angle thereto.

11. An apparatus according to claim 1 wherein the rotation of said arm member is synchronized with the forward movement speed of the'blank so that the portion of the arm member contacti the blank moves at the same general forward speed as the b ank .during its period of contact with the blank whereby the arm member contacts the blank in the region of said fold line before the folding of said flaps by said folding means begins and said arm member remains in the region of said fold line as said blank moves and until said fold line is clearly established.

12. Apparatus for folding an outwardly extending generally coplanar longitudinally flap at an edge of a blank out of the plane of the blank as the latter is being advanced longitudinally, said apparatus comprising conveyor means for longitudinally advancing a blank of material having opposite surfaces and a longitudinal flap extending from a rear portion of the blank adjacent a lateral edge thereof, folding means for acting on the flap of the advancing blank to fold the same about a fold line forwardly out of the plane of said blank, and restraining means synchronized with said folding means and said conveyor means to contact the blank in the region of the fold line as said blank is advancing. said restraining means acting in cooperation with said folding means as the flap is being folded to contact the blank on the surface thereof opposite that engaged by said folding means in the region of said fold line and exert pressure on said blank proximate said edge to hold the edge in position as the flaps are being folded, said restraining means comprising an elongated rotatable arm member which rotates in a plane of rotation which is incline with respect to the plane of the blank.

13. An apparatus according to claim 12 wherein said arm member contacts the blank in the region just ahead of the fold line to hold the edge of the blank in its plane and to prevent raising thereof, said arm members remaining in contact with the blank as it is being advanced until the flap has been folded through a sufficient angle so there is no longer any tendency for the edge of the blank to be raised. 

